An automotive vehicle typically includes an internal combustion engine containing a rotary crankshaft configured to transfer motive power from the engine through a driveshaft to turn the wheels. A transmission is interposed between engine and driveshaft components to selectively control torque and speed ratios between the crankshaft and driveshaft. In a manually operated transmission, a corresponding manually operated clutch may be interposed between the engine and transmission to selectively engage and disengage the crankshaft from the driveshaft to facilitate manual shifting among available transmission gear ratios. On the other hand, if the transmission is automatic, the transmission will normally include an internal plurality of automatically actuated clutch units adapted to dynamically shift among variously available gear ratios without requiring driver intervention. Pluralities of such clutch units, also called clutch modules, are incorporated within such transmissions to facilitate the automatic gear ratio changes.
Multi-mode clutch modules (MMCMs) have become an important part of transmission designs in order to meet government fuel efficiency standards. The MMCMs can take the place of friction plates that are currently used in many applications. This is accomplished using two sets of pawls (a forward pawl set and a reverse pawl set) that are moved by an actuator of the MMCM. The forward pawl set will prevent rotation in one direction (clockwise will be used for clarification, but the direction of the rotation depends on the transmission design) and the reverse pawl set prevents rotation in the opposite direction (i.e., counterclockwise as used herein). The pawls are designed to be movable between engaged and disengaged positions to alternately lock and unlock an inner race relative to an outer race or notch ring of the MMCM. The forward and reverse pawl sets can be actuated in concert or independently to provide up to four modes for the MMCM: locked in both directions, one-way locking in the clockwise direction, one-way locking in the counterclockwise direction, and unlocked to allow free rotation in both directions.
In some applications, a clutch is used to connect two members that are both rotating. In many of these applications, however, it is not practical to have an actuator that rotates with the inner race or the outer race. Rotation of the actuator along with the race on which it is mounted can cause wires of the actuator to twist or create excessive drag on the MMCM that can reduce the efficiency of the vehicle or other machine in which the MMCM is implemented.